CN110527824B - Additive for inhibiting low-temperature reduction degradation of iron ore sinter, iron ore sinter and preparation method of iron ore sinter - Google Patents

Abstract

The invention discloses an additive for inhibiting low-temperature reduction degradation of iron ore sinter, the iron ore sinter and a preparation method thereof, and the additive comprises the following components in percentage by mass: 5 to 20 percent of main additive and 0.5 to 1 percent of auxiliary0.5 to 1 percent of dispersant and the balance of water; wherein, the main additive contains 20 to 35 percent of Ba²⁺20 to 30 percent of Mg²⁺And 10% to 30% of V⁵⁺The auxiliary agent is comb-type alkylphenol polyoxyethylene ether or comb-type polyether polysiloxane, and the dispersing agent is polyethylene glycol 200 or polyethylene glycol 400. The additive for inhibiting the low-temperature reduction degradation of the iron ore sinter is uniformly added into the sintering raw material during mixing and wetting, then granulation is carried out, and the mixture is distributed and sintered on a sintering machine to obtain the sinter, which can effectively inhibit the low-temperature reduction degradation of the sinter and optimize the low-temperature Reduction Degradation Index (RDI) of the sinter_+3.15) The quality of the sinter is improved, and the smooth operation of the blast furnace is facilitated.

Description

Additive for inhibiting low-temperature reduction degradation of iron ore sinter, iron ore sinter and preparation method of iron ore sinter

Technical Field

The invention belongs to the field of iron-making sintering, and particularly relates to an additive for inhibiting low-temperature reduction degradation of an iron ore sinter, the iron ore sinter and a preparation method of the iron ore sinter.

Background

The mechanism of low-temperature reduction and pulverization of sintered ore is that the skeleton-shaped hematite (also called regenerated hematite) is reduced at low temperature and lattice transition (alpha Fe) occurs₂O₃Conversion to gamma Fe₂O₃Hexagonal lattice is changed into cubic lattice in the process), and great internal stress is generated, so that the sintering ore is cracked, cracked and pulverized in different degrees, the air permeability of a charge column in the furnace is poor, the pressure difference is increased, the production efficiency is influenced, the energy consumption is increased, and the economic benefit of iron and steel enterprises is reduced. Therefore, it is extremely necessary to improve the index of reduction degradation of the sintered ore as much as possible.

At present, the measures for inhibiting the low-temperature reduction degradation of the sinter comprise the following measures: 1) properly improving the alkalinity of the sintered ore; 2) low temperatureSintering; 3) CaO is separately granulated; 4) the thickness of the material layer is increased; 5) the sinter is treated with an aqueous halide solution. In the production practice, the spraying of low-temperature reduction pulverization additives on the sinter becomes a main means for inhibiting the pulverization of the sinter. The current inhibitor is mainly chloride (such as CaCl)₂、MgCl₂) Mainly used and applied in actual production to obtain certain effect. The Cl element can not only corrode metal equipment, but also be a component element of a highly toxic substance dioxin, and the environmental pollution is aggravated by using a large amount of inhibitor. Therefore, in order to meet the requirements of energy conservation, emission reduction and environmental pollution reduction for the steel industry, the research on the low-humidity reduction pulverization non-chlorine environment-friendly additive for the sinter has important practical significance.

Disclosure of Invention

The invention aims to provide an additive for inhibiting low-temperature reduction degradation of an iron ore sinter, the iron ore sinter and a preparation method thereof, and aims to overcome the defects that Cl element in an inhibitor in the prior art causes great pollution to the environment and is not environment-friendly.

The technical scheme adopted by the invention is as follows:

an additive for inhibiting low-temperature reduction degradation of iron ore sinter comprises the following components in percentage by mass: 5 to 20 percent of main additive, 0.5 to 1 percent of auxiliary agent, 0.5 to 1 percent of dispersant and the balance of water;

the main additive comprises a component A, a component B and a component C, wherein the component A is one or two of barium nitrate and barium hydroxide, the component B is magnesium nitrate, and the component C is sodium metavanadate.

In the main additive, Ba is calculated by mass percent²⁺20 to 35 percent of Mg²⁺Content of 10% -20%, V⁵⁺The content is 10-20%.

The auxiliary agent is comb-type alkylphenol polyoxyethylene ether or comb-type polyether polysiloxane.

The dispersant is polyethylene glycol 200 or polyethylene glycol 400.

A method for preparing the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter comprises the following steps:

uniformly mixing the component A, the component B and the component C to prepare a main additive;

and uniformly mixing the main additive, the auxiliary agent, the dispersing agent and water to obtain the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter.

An iron ore sinter to which the additive for suppressing low-temperature reduction degradation of the iron ore sinter is added.

In the iron ore sintered ore, the mass of the additive for inhibiting the low-temperature reduction degradation of the iron ore sintered ore is 1-3% of the mass of the sintering raw material.

A method for preparing the iron ore sinter, comprising the steps of:

and adding the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter into the sintering raw materials uniformly during mixing and wetting, then granulating, sintering and cooling to obtain the iron ore sinter.

The invention has the following beneficial effects:

the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter starts from sintering raw material ingredients, and comprises a main additive, an auxiliary agent and a dispersing agent, wherein the main additive contains Ba²⁺、Mg²⁺And V^{5 +}The additive does not contain Cl element, thereby overcoming the corrosion of Cl element to equipment and environmental pollution. In the additive, the components of the main additive are soluble compounds, so that the solubility is higher, and the inhibition effect can be enhanced; the auxiliary agent has the function of inhibiting the crystallization of the additive, so that the blockage of blowing equipment is avoided; the dispersing agent can make the additive distribute in the sintering raw material quickly. Ba in the inventive additive²⁺And Mg²⁺Capable of being mixed with Fe in raw material for sintering iron ore sinter₂O₃And SiO₂A reaction takes place, and V⁵⁺Promoting barium-containing compound and Fe₂O₃The reaction can generate more ferrite and barium ferrite, can effectively enhance the strength of the iron ore sinter and reduce Fe in the reduction process₂O₃Thereby suppressing Fe₂O₃To Fe₃O₄And reducing, weakening the pulverization phenomenon caused by crystal form transformation and obtaining good low-temperature reduction pulverization index.

When the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter is prepared, the component A, the component B and the component C are uniformly mixed to prepare a main additive; and then uniformly mixing the main additive, the auxiliary agent, the dispersing agent and water to obtain the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter, wherein the preparation process is simple and convenient, and the requirement on equipment is low.

The iron ore sinter added with the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter does not contain Cl element, so that the corrosion of the Cl element to equipment is avoided, the generation of a highly toxic substance dioxin is avoided, and the method has the advantage of environmental friendliness; at the same time, has good low-temperature reduction degradation index, in particular DRI_+6.380.61-83.58, DRI_+3.1587.49 to 90.76, DRI_-0.5Is 3.06 to 4.72.

According to the method for preparing the iron ore sinter, the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter is uniformly added into the sintering raw materials during mixing and wetting, then granulation and sintering are carried out, and then the iron ore sinter is obtained after cooling.

Detailed Description

The invention is further illustrated by the following examples:

the mixture (sinter raw material) of a certain sintering plant in China is taken as an experimental raw material, the additive related to the invention is added, then the mixture is fully mixed and granulated, then a sintering experiment is carried out, and the finished sinter cooled to room temperature is detected by a static method according to the national standard of China (GB/T13242-91) to reduce the degradation index (DRI)_+6.3、DRI_+3.15、DRI_-0.5Representation), wherein:

in the formula, M_D0The mass of the sample before the drum test is given as g;

M_D1the mass of the sample left on the 6.3mm sieve is given in g;

M_D2the mass of the sample retained on the 3.15mm sieve is given in g;

M_D3the mass of the sample left on the 0.5mm sieve is given in g;

RDI_+6.3the percentage of particles with the particle size of more than 6.3mm in the sample before testing;

RDI_+3.15the percentage of particles with the grain diameter larger than 3.15mm in the sample before testing;

RDI_-0.5is the percentage of particles with a particle size of less than 0.5mm to the sample before testing.

Comparative example

Granulating the experimental raw materials, carrying out a sintering experiment, and cooling the finished sintered ore to room temperature to obtain the DRI of the prepared iron ore sintered ore_+6.3、DRI_+3.15And DRI_-0.5The statistical results are shown in Table 1.

Example 1

The process for preparing the iron ore sinter of the embodiment comprises the following steps:

1) uniformly mixing barium nitrate, magnesium nitrate and sodium metavanadate to prepare a main additive, wherein the contents of barium nitrate, magnesium nitrate and sodium metavanadate in the main additive are respectively 30.83%, 49.83% and 19.34% by mass percent; the corresponding main additive contains 20 mass percent of Ba²⁺10% of Mg²⁺And 10% of V⁵⁺。

2) The main additive, the comb-type alkylphenol polyoxyethylene ether, the polyethylene glycol 200 and the water are uniformly mixed to prepare the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter, wherein the main additive, the comb-type alkylphenol polyoxyethylene ether and the polyethylene glycol 200 respectively account for 5%, 0.5% and 0.6% in percentage by mass, and the balance is the water.

And uniformly adding the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter into the sintering raw materials by adopting a water pump during mixing and wetting, then granulating, sintering and cooling to obtain the iron ore sinter, wherein the addition amount of the additive is 1.2% of the mass of the experimental raw materials. The DRI of the iron ore sinter prepared in this example was obtained by reducing and detecting the reduction degradation index of the iron ore sinter by a static method_+6.3、DRI_+3.15And DRI_-0.5The statistical results are shown in Table 1.

Example 2

1) Uniformly mixing barium hydroxide, magnesium nitrate and sodium metavanadate to prepare a main additive, wherein the contents of the barium hydroxide, the magnesium nitrate and the sodium metavanadate in the main additive are respectively 19.51%, 54.48% and 26.01% by mass percent; the corresponding main additive contains 23 mass percent of Ba²⁺13% of Mg²⁺And 16% of V⁵⁺。

2) The main additive, the comb-type polyether polysiloxane, the polyethylene glycol 400 and water are uniformly mixed to prepare the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter, wherein the main additive, the comb-type polyether polysiloxane and the polyethylene glycol 400 are respectively 12%, 0.7% and 0.8% in percentage by mass, and the balance is water.

And uniformly adding the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter into the sintering raw materials by adopting a water pump during mixing and wetting, then granulating, sintering and cooling to obtain the iron ore sinter, wherein the addition amount of the additive is 2.8 percent of the mass of the experimental raw materials. The DRI of the iron ore sinter prepared in this example was obtained by reducing and detecting the reduction degradation index of the iron ore sinter by a static method_+6.3、DRI_+3.15And DRI_-0.5The statistical results are shown in Table 1.

Example 3

1) Uniformly mixing a mixture of barium nitrate and barium hydroxide, magnesium nitrate and sodium metavanadate to prepare a main additive, wherein the main additive contains, by mass percent, 9.52% of barium nitrate, 14.56% of barium hydroxide, 50.65% of magnesium nitrate and 25.27% of sodium metavanadate; the corresponding main additive contains 26 mass percent of Ba²⁺14% of Mg²⁺And 18% of V⁵⁺。

2) The main additive, the comb-type polyether polysiloxane, the polyethylene glycol 200 and the water are uniformly mixed to prepare the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter, wherein the main additive, the comb-type polyether polysiloxane and the polyethylene glycol 200 are respectively 7%, 0.6% and 0.9% in percentage by mass, and the balance is the water.

And uniformly adding the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter into the sintering raw materials by adopting a water pump during mixing and wetting, then granulating, sintering and cooling to obtain the iron ore sinter, wherein the addition amount of the additive is 0.98 percent of the mass of the experimental raw materials. The DRI of the iron ore sinter prepared in this example was obtained by reducing and detecting the reduction degradation index of the iron ore sinter by a static method_+6.3、DRI_+3.15And DRI_-0.5The statistical results are shown in Table 1.

Example 4

1) Uniformly mixing magnesium nitrate, barium hydroxide and sodium metavanadate to prepare a main additive, wherein the contents of barium hydroxide, magnesium nitrate and sodium metavanadate in the main additive are respectively 21.98%, 63.06% and 14.96% by mass percent; the corresponding main additive contains 31 mass percent of Ba²⁺18% of Mg²⁺And 11% of V⁵⁺。

2) The main additive, the comb-type alkylphenol polyoxyethylene ether, the polyethylene glycol 200 and the water are uniformly mixed to prepare the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter, wherein the main additive, the comb-type alkylphenol polyoxyethylene ether and the polyethylene glycol 200 are respectively 20%, 0.9% and 0.8% in percentage by mass, and the balance is the water.

And uniformly adding the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter into the sintering raw materials by adopting a water pump during mixing and wetting, then granulating, sintering and cooling to obtain the iron ore sinter, wherein the addition amount of the additive is 2.1 percent of the mass of the experimental raw materials. The DRI of the iron ore sinter prepared in this example was obtained by reducing and detecting the reduction degradation index of the iron ore sinter by a static method_+6.3、DRI_+3.15And DRI_-0.5The statistical results are shown in Table 1.

Example 5

1) Uniformly mixing a mixture of barium nitrate and barium hydroxide, magnesium nitrate and sodium metavanadate to prepare a main additive, wherein the main additive contains, by mass, 13.75% of barium nitrate, 8.76% of barium hydroxide, 56.62% of magnesium nitrate and 20.87% of sodium metavanadate; the corresponding main additive contains 34% of Ba by mass percentage²⁺20% of Mg²⁺And 19% of V⁵⁺。

2) The main additive, the auxiliary comb-type polyether polysiloxane, the polyethylene glycol 400 and water are uniformly mixed to prepare the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter, wherein the main additive, the auxiliary comb-type polyether polysiloxane and the polyethylene glycol 400 are respectively 19%, 0.6% and 0.7% in percentage by mass, and the balance is water.

And uniformly adding the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter into the sintering raw materials by adopting a water pump during mixing and wetting, then granulating, sintering and cooling to obtain the iron ore sinter, wherein the addition amount of the additive is 1.7 percent of the mass of the experimental raw materials. The DRI of the iron ore sinter prepared in this example was obtained by reducing and detecting the reduction degradation index of the iron ore sinter by a static method_+6.3、DRI_+3.15And DRI_-0.5The statistical results are shown in Table 1.

TABLE 1

As can be seen from the results in Table 1, the DRI results of the iron ore sintered ore to which the additive of the present invention was added were superior to those of the iron ore sintered ore raw ore.

In summary, the additive for inhibiting reduction degradation of sintered ore comprises a main additive, an auxiliary agent and a dispersing agent from the raw material ingredients of sintering, wherein the cation in the main additive is Ba²⁺、Mg²⁺And V⁵⁺The assistant is comb alkylphenol polyoxyethylene ether or comb polyether polysiloxane, and the dispersant is polyethylene glycol 200 or polyethylene glycol 400, so that the additive does not contain Cl element, and overcomes the corrosion of Cl element to equipment and environmental pollution. The main additive is selected from soluble compounds, so that the solubility is higher, and the inhibition effect is enhanced; the auxiliary agent has the function of inhibiting the crystallization of the additive, so that the blockage of blowing equipment is avoided; the dispersing agent can make the additive distribute in the sintering raw material quickly. Ba in the additive added²⁺、Mg²⁺Can react with Fe₂O₃、SiO₂A reaction takes place, and V⁵⁺Promoting barium-containing compound and Fe₂O₃The reaction can generate more ferrite and barium ferrite, effectively enhance the strength of the sinter and reduce Fe in the reduction process₂O₃Thereby suppressing Fe₂O₃To Fe₃O₄And reducing, weakening the pulverization phenomenon caused by crystal form transformation and obtaining good low-temperature reduction pulverization index.

Claims (7)

1. An additive for inhibiting low-temperature reduction degradation of iron ore sinter is characterized by comprising the following components in percentage by mass: 5 to 20 percent of main additive, 0.5 to 1 percent of auxiliary agent, 0.5 to 1 percent of dispersant and the balance of water;

the main additive comprises a component A, a component B and a component C, wherein the component A is one or two of barium nitrate and barium hydroxide, the component B is magnesium nitrate, and the component C is sodium metavanadate;

the auxiliary agent is comb-type alkylphenol polyoxyethylene ether or comb-type polyether polysiloxane.

2. The additive for suppressing low-temperature reduction degradation of iron ore sinter as claimed in claim 1, wherein Ba is contained in the main additive in mass percentage²⁺20 to 35 percent of Mg²⁺Content of 10% -20%, V⁵⁺The content is 10-20%.

3. The additive for suppressing low-temperature reduction degradation of iron ore sinter as claimed in claim 1, wherein the dispersant is polyethylene glycol 200 or polyethylene glycol 400.

4. A method for preparing the additive for suppressing low-temperature reduction degradation of iron ore sinter as claimed in any one of claims 1 to 3, which comprises the following steps:

uniformly mixing the component A, the component B and the component C to prepare a main additive;

and uniformly mixing the main additive, the auxiliary agent, the dispersing agent and water to obtain the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter.

5. An iron ore sinter to which the additive for suppressing low-temperature reduction degradation of the iron ore sinter as claimed in any one of claims 1 to 3 is added.

6. The iron ore sinter as claimed in claim 5, wherein the additive that suppresses the low-temperature reduction degradation of the iron ore sinter has a mass that is 1 to 3% of the mass of the sintering material.

7. A method for producing the iron ore sinter as claimed in claim 5 or 6, which comprises the steps of:

and adding the additive for inhibiting the low-temperature reduction degradation of the iron ore sinter into the sintering raw materials uniformly during mixing and wetting, then granulating, sintering and cooling to obtain the iron ore sinter.